In the UMTS (Universal Mobile Telecommunications System) network, for the purposes of further increasing high-speed data rates, providing low delay and so on, long-term evolution (LTE) has been under study (see, for example, non-patent literature 1). In LTE, as multiple access schemes, a scheme that is based on OFDMA (Orthogonal Frequency Division Multiple Access) is used on the downlink, and a scheme that is based on SC-FDMA (Single Carrier Frequency Division Multiple Access) is used on the uplink.
Also, for the purpose of achieving further broadband and higher speed beyond LTE, a successor system of LTE has been under study. This successor system may be referred to as “LTE advanced” or “LTE enhancement” (hereinafter referred to as “LTE-A”). In LTE (Rel. 8) and LTE-A (Rel. 9 and Rel. 10), MIMO (Multi-Input Multi-Output) techniques to improve spectral efficiency by transmitting and receiving data by a plurality of antennas are under study as a radio communication technique. In the MIMO system, a plurality of transmitting/receiving antennas are provided in the transmitter/receiver, so that different transmission information sequences are transmitted from different transmitting antennas, at the same time.